Modelling of a radial pump fast startup with the CATHARE-3 Code and analyse of the loop response

International audienceThe french alternative energies and atomic energy commission (CEA) is currently doingresearch in the pump modelling field. A predictive transient, two-phase flow rotodynamicpump model has been developed in the CATHARE-3 code. Flow inside parts of the pump(suction, impeller, diffuser, volute) is computed according to a one-dimensional discretization.A mean flow path has to be defined for such a modelling. Validation has startedduring years 2017-18 at the component scale by comparison to an existing experimentaldatabase. The ability of the model to predict head and torque as a function of time duringa 1-second pump fast start-up has been proved when imposing rotational speed and flowrate evolutions. The present study aims at extending the validation at the system scale awhole loop is modelled